As the back cover of a watchcase is being screwed onto the middle part of the case, it frequently happens that, when the back cover is completely screwed on, one can see that the decorative markings or designs which may have been made for example by die stamping or engraving on the face of the back cover located on the side of the watch wearer's wrist, are not properly aligned with respect to the vertical 12 o'clock-6 o'clock axis of said watch, which, of course, is detrimental to the aesthetic appearance of said watch.
While this defective appearance may be tolerated for inexpensive watches, it constitutes a very inconvenient drawback for more expensive watches.
In order to overcome this drawback, the only solution known to date consists in coupling a back cover to a determined watchcase during machining, so as to ensure that, once completely screwed on, the back cover is perfectly aligned with the 12 o'clock-6 o'clock axis of the watch. This solution is however unsatisfactory since problems arise if the original back cover of the watch is ever lost or ruined and it becomes necessary to replace it with another back cover, which, one cannot be sure, will still be properly aligned with the vertical 12 o'clock-6 o'clock axis, once it is screwed onto the middle part.
The object of the present invention is to overcome this drawback in addition to others by proposing a system which, after screwing a back cover onto the middle part of a watchcase, enables the alignment of the back cover to be adjusted simply and efficiently with respect to the 12 o'clock-6 o'clock axis of the watch, so as to guarantee the proper disposition of the markings and other decorative designs which have been added to the face of the back cover of the watch oriented towards the side of the watch wearer's wrist.